Tropical Conservation Biology and Environmental Science, University of Hawai'i at Hilo, 200 West Kawili Street, Hilo, Hawaii 96720, USA.
Ecol Appl. 2013 Sep;23(6):1367-83. doi: 10.1890/12-0529.1.
Poeciliids, one of the most invasive species worldwide, are found on almost every continent and have been identified as an "invasive species of concern" in the United States, New Zealand, and Australia. Despite their global prevalence, few studies have quantified their impacts on tropical stream ecosystem structure, function, and biodiversity. Utilizing Hawaiian streams as model ecosystems, we documented how ecological structure, function, and native species abundance differed between poeciliid-free and poeciliid-invaded tropical streams. Stream nutrient yields, benthic biofilm biomass, densities of macroinvertebrates and fish, and community structures of benthic algae, macroinvertebrates, and fish were compared between streams with and without established poeciliid populations on the island of Hawai'i, Hawaii, USA. Sum nitrate (sigmaNO3(-) = NO3(-) + NO2(-)), total nitrogen, and total organic carbon yields were eight times, six times, and five times higher, respectively, in poeciliid streams than in poeciliid-free streams. Benthic biofilm ash-free dry mass was 1.5x higher in poeciliid streams than in poeciliid-free streams. Percentage contributions of chironomids and hydroptilid caddisflies to macroinvertebrate densities were lower in poeciliid streams compared to poeciliid-free streams, while percentage contributions of Cheumatopsyche analis caddisflies, Dugesia sp. flatworms, and oligochaetes were higher. Additionally, mean densities of native gobies were two times lower in poeciliid streams than in poeciliid-free ones, with poeciliid densities being approximately eight times higher than native fish densities. Our results, coupled with the wide distribution of invasive poeciliids across Hawaii and elsewhere in the tropics, suggest that poeciliids may negatively impact the ecosystem structure, function, and native species abundance of tropical streams they invade. This underscores the need for increased public awareness to prevent future introductions and for developing and implementing effective eradication and restoration strategies.
胎鱂鱼，世界上最具入侵性的物种之一，几乎在各大洲都有发现，并已被确定为美国、新西兰和澳大利亚的“关注入侵物种”。尽管它们在全球范围内广泛存在，但很少有研究量化它们对热带溪流生态系统结构、功能和生物多样性的影响。利用夏威夷溪流作为模型生态系统，我们记录了在没有和有胎鱂鱼种群的情况下，生态结构、功能和本地物种丰度如何在热带溪流中有所不同。我们比较了美国夏威夷岛有和没有胎鱂鱼种群的溪流中溪流养分产量、底栖生物膜生物量、大型无脊椎动物和鱼类密度以及底栖藻类、大型无脊椎动物和鱼类群落结构。胎鱂鱼溪流中的总硝酸盐（ΣNO3(-) = NO3(-) + NO2(-)）、总氮和总有机碳产量分别比无胎鱂鱼溪流高 8 倍、6 倍和 5 倍。胎鱂鱼溪流中的底栖生物膜灰分干重比无胎鱂鱼溪流高 1.5 倍。与无胎鱂鱼溪流相比，胎鱂鱼溪流中摇蚊和Hydroptilidae 蜉蝣的密度百分比较低，而Cheumatopsyche analis 蜉蝣、Dugesia sp. 扁形动物和寡毛纲的百分比较高。此外，胎鱂鱼溪流中本地虾虎鱼的平均密度比无胎鱂鱼溪流低两倍，而胎鱂鱼的密度比本地鱼类的密度高约 8 倍。我们的研究结果，加上入侵胎鱂鱼在夏威夷和热带其他地区的广泛分布，表明胎鱂鱼可能会对其入侵的热带溪流的生态系统结构、功能和本地物种丰度产生负面影响。这突显了需要提高公众意识，以防止未来的引入，并制定和实施有效的根除和恢复策略。
